Thanks for your comments Dave.

Yes I've identified a donor model; a Revell 1/72 scale Type VIIC/41.

I've calculated that converting the measurements from 1/72 to 1/48 is a simple case of multiplying by a factor of 1.5 so shouldn't pose a problem.

The thing with two-dimensional drawings, especially for what i'm after, is that they don't depict the rake of the angle at the rear of the tower which is crucial.

Evening Everyone.

Another post from the dry dock [my kitchen]

On this part of the build i'm focusing on the free flood holes above the Torpedo Compartment and the free flood holes just behind them. All will become apparent when you see the pictures.

After thoroughly digesting Dougie Martindales article regarding the patterns of the free flood holes, it appears there was no pattern to fit all. Many U-Boats had different numbers of holes compared to others and port and starboard sides varied too.

Just to make it clear, the free flood holes allowed the sea water to literally flood in under the casing [top deck]. The reason for this was to ensure the sea pressure was equal inside and out to prevent the casing from being crushed when the boat was dived.

After studying the only two pictures I could find of U230 coupled with the article by Dougie Martindale it transpires that the amount of free flood holes above the Torpedo compartment supplied by the part-works was the correct configuration and number on the port side.

The starboard side however required two extra holes added, one forward of the original pattern and an extra one aft of the pattern.

The attached photo shows the starboard side, bow to the right with the two holes marked out ready for drilling, grinding and filing.

This photo shows the aft hole marked out.

Similarly, this photo shows the pilot holes drilled through on the after one.

This photo shows the forward hole, roughed out and starting to take shape. More dressing with the needle file required.

This photo shows the completed rear hole.

That concludes this part.

From the previous picture you can see the long row of smaller holes that run along the top.

These are the ones I will be focusing on next.

Studying actual U230 photos and again referring back to Dougie's article it transpires that the Kriegsmarine decided to modify this arrangement sometime during the early part of 1942. By modifying, what I mean is the removal of. After trials the Admiralty concluded that the inclusion of them originally didn't actually speed up and aid emergency dives. Also, these extra holes would vent air whilst the boat was diving creating more bubbles that could be spotted from the air; hence their omission on later boat builds.

U230 was never fitted with them when built, so I had to block these off to make the model more historically accurate.

Using 2mm and 2.5mm plastic rod I could plug these holes without too much difficulty. Cutting, then filing smooth after to match the contour of the hull.

The first photo shows the 2mm plastic rod glued in place prior to cutting. I figured it was more prudent to glue the rod in place and use it's length as a temporary handle while the glue set rather than fiddle about with small dowel like sections.

The next image shows the rod cut. At this stage the rod was still sitting proud of the hull and requires dressing and sanding.

Another angled view of the Port side hull.

This is the Starboard side of the hull.